Self sheathing safety needle

Abstract

A self sheathing safety needle comprising a needle assembly (50), a needle guard (52), and an outer casing (54) is shown in exploded relation in FIG. 1 . Needle guard (52) has a locking tab (100) mounted on the free end of a spring finger or lever (98). Locking tab (100) is received within an internal track on outer casing (54) which has a cam lug (148) for effecting movement of locking tab (100) between a locked extended position of the needle guard (52) and an unlocked extended position of the needle guard (52) to permit retraction of the needle guard (52). Casing (54) is mounted for limited rotation on bearings (60, 62) on the hub (86) of the needle assembly (50) to effect movement of the locking tab (100) to an unlocked position. Stops (76, 78, 80, 82) on bearings (60, 62) limit relative rotation of casing (54) between locked and unlocked positions of needle guard (52) and locking tab (100). During injection, the end (104) of the needle guard (52) is always in contact with the patient, and the needle (50) is never exposed, thus unable to inflict an accidental needle-stick injury. When needle (50) is withdrawn from the patient, locking tab (100) automatically travels along track (145), and is cammed into a locked extended position by the cam lug (148) and associated adjacent surfaces.

I claim: 
     
       1. A self sheathing needle device comprising: a needle assembly including a base on one end thereof and a hollow needle extending from said base for the injection or aspiration of a fluid;   an elongate hollow needle guard member movable relative to said needle assembly between an extended locked position, an extended unlocked position, and a plurality of retracted unlocked positions;   an elongate outer casing member surrounding and receiving said needle guard member in a telescoping relation and rotatably connected at one end to said base, said needle guard member extending outwardly from an opposed end of said casing member;   means within said elongate outer casing member to bias said needle guard member continuously toward one of said extended positions;   means mounting said outer casing member and said needle guard member for relative rotation and for relative longitudinal movement; and   coacting guide means on said outer casing member and said needle guard member to control relative movement between said casing member and said needle guard member for guiding said needle guard member between said locked and unlocked positions, said coacting guide means including a resilient locking element on one member movable resiliently in a generally radial direction relative to the other member for locking said needle guard member in said extended locked position.   
     
     
       2. A self sheathing needle device as set forth in claim 1 wherein: said coacting guide means includes a guide for said locking element mounted on said other member for guiding said needle guard member between said locked and unlocked positions, said needle guard member moving from said extended locked position to said extended unlocked position only upon rotation of said casing member relative to said needle guard member.   
     
     
       3. A self sheathing needle device as set forth in claim 2 wherein: said guide comprises a track in which said locking element 15 mounted for relative sliding movement and for relative rotational movement, said track including a ramp for caming said locking element in a generally radial direction for locking and unlocking of said locking element.   
     
     
       4. A self sheathing needle device as set forth in claim 2 wherein: said resilient locking element comprises a resilient finger having an extended free end thereof and a locking tab on said extended free end.   
     
     
       5. A self sheathing needle device as set forth in claim 4 herein: said guide comprises a track on which said locking tab is mounted for sliding movement and for relative rotative movement, said track including a ramp for caming said locking element in a generally radial direction for locking of said locking tab.   
     
     
       6. A self sheathing needle device comprising: a needle assembly including a hollow needle for the injection or aspiration of a fluid;   an elongate hollow needle guard member movable between an extended locked position, an extended unlocked position, and a plurality of retracted unlocked positions;   an elongate casing member surrounding said needle guard member in a telescoping relation;   means to bias said needle guard member continuously toward one of said extended positions;   means mounting said casing member and said needle guard member for relative rotation and for relative longitudinal movement; and   coacting guide means on said casing member and said needle guard member to control relative movement between said casing member and said needle guard member for guiding said needle guard member between said locked and unlocked positions, said coacting guide means including a resilient locking element on one member movable in a generally radial direction relative to the other member for locking said needle guard member in said extended locked position;   said needle assembly having a base on one end thereof for securing said hollow needle with said needle extending therefrom and terminating at a free outer end;   said hollow needle guard member having an inner guide receiving said base in a nonrotative relation while permitting sliding movement of said hollow needle guard member along said base in a longitudinally extending axial relation, said needle guard member extending beyond said free outer end of said needle in locked and unlocked extended positions.   
     
     
       7. A self sheathing needle device as set forth in claim 6 wherein: said hollow needle guard member comprises a large diameter rear cylindrical hollow portion and an integral small diameter forward cylindrical hollow portion, said large diameter cylindrical portion including said inner guide and movable along said base of said needle assembly; and   said means to bias comprises a coil spring extending about said base of said needle assembly and engaging said large diameter cylindrical portion of said needle guard member for continuously urging said needle guard member to one of said extended positions.   
     
     
       8. A self sheathing needle device as set forth in claim 6 wherein: said base includes an outer hub portion operable for releasable connection to a medical device, said hub portion including a bearing member engaging said casing member and supporting said casing member for relative rotative movement upon rotation of said casing member.   
     
     
       9. A self sheathing needle device as set forth in claim 8 wherein: a pair of spaced stops are provided adjacent said bearing member for limiting relative rotative movement of said casing member.   
     
     
       10. A self sheathing needle device as set forth in claim 7 wherein: said hollow casing member has a large diameter opening adjacent an outer end to receive said large diameter portion of said needle guard member therein and a small diameter opening adjacent an inner end to receive said small diameter cylindrical portion of said needle guard member, said needle guard member mounted for sliding longitudinal movement within said hollow casing member.   
     
     
       11. A self sheathing needle device as set forth in claim 9 wherein: said casing member has a bearing member coacting with said bearing member on said hub portion of said base, said casing member including a stop member coacting with said pair of spaced stops on said bearing member of said needle assembly for limiting rotational movement of said casing member.   
     
     
       12. A self sheathing needle device comprising: an integral needle assembly having a base on one end thereof and a hollow needle extending from said base terminating at a free outer end;   an elongate hollow needle guard member movable between an extended locked position, an extended unlocked position, and a plurality of retracted unlocked positions; said hollow needle guard member including a large diameter rear cylindrical portion and an integral small diameter forward cylindrical portion;   an outer hollow cylindrical casing member having a large diameter end opening at an outer end thereof and a small diameter end opening at an inner end thereof, said needle guard member fitting within said outer casing member in telescoping relation for relative sliding movement with said small diameter cylindrical portion extending through said small diameter end opening;   a coil spring extending about said base of said needle assembly and engaging said large diameter cylindrical portion of said needle guard member for continuously urging said needle guard assembly to one of said extended positions; and   coacting guide means on said outer casing member and said needle guard member to permit relative rotation of said members between said extended locked position and said extended unlocked position, said needle guard member receiving said hollow needle and projecting beyond said free outer end of said needle in said extended locked position and said extended unlocked position.   
     
     
       13. A self sheathing needle device as set forth in claim 12 wherein: said coacting guide means includes a resilient finger on one member having a locking tab on said finger; and   a track on the other member in which said locking tab is mounted for sliding movement and for relative rotative movement.   
     
     
       14. A self sheathing needle device as set forth in claim 13 wherein: said track includes a ramp for caming said locking tab in a generally radial direction for locking and unlocking of said needle guard member.   
     
     
       15. A self sheathing needle device as set forth in claim 13 wherein: said base includes an outer hub portion operable for releasable connection to a medical device, said hub portion including an outer arcuate bearing member supporting said casing member for relative rotative movement upon rotation of said casing member.   
     
     
       16. A self sheathing needle device as set forth in claim 15 wherein: a pair of spaced stops are provided adjacent said bearing member for limiting relative rotative movement of said casing member.   
     
     
       17. A self sheathing needle device as set forth in claim 15 wherein: said casing member has an inner arcuate bearing member coacting with said outer bearing member on said hub portion of said base, said casing member including a stop for coacting with said pair of spaced stops on said bearing member of said needle assembly for limiting rotational movement of said casing member relative to said needle guard member.   
     
     
       18. A self sheathing needle device comprising: an integral needle assembly having a base on one end thereof and a hollow needle extending from said base terminating at a free outer end;   an elongate hollow needle guard member movable between an extended locked position, an extended unlocked position, and a plurality of retracted unlocked positions; said hollow needle guard member including a large diameter rear portion and an integral small diameter forward portion;   an outer casing member having an end opening at an inner end thereof, said needle guard member fitting within said outer casing member in telescoping relation for relative sliding movement with said small diameter forward portion extending through said end opening;   means continuously urging said needle guard assembly to one of said extended positions;   first coacting guide means on said outer casing and said needle guard member to permit relative manual rotation of said members, said needle guard member receiving said hollow needle and projecting beyond said free outer end of said needle in said extended locked position and said extended unlocked position; and   second coacting guide means on said base of said needle assembly and said needle guard member to permit sliding longitudinal movement of said needle guard member relative to said base.   
     
     
       19. A self sheathing needle device as set forth in claim 18 wherein: said base includes an outer hub portion operable for releasable connection to a medical device, said hub portion including an arcuate bearing member supporting said casing member for relative rotative movement upon rotation of said casing member; and   a pair of spaced stops are provided adjacent said bearing member for limiting relative rotative movement of said casing member.   
     
     
       20. A self sheathing needle device as set forth in claim 19 wherein: said casing member has an inner arcuate bearing member coacting with said outer bearing member on said hub portion of said base, said casing member including a stop for coacting with said pair of spaced stops on said bearing member of said needle assembly for limiting rotational movement of said casing member relative to said needle guard member.